The present invention relates to a method and apparatus for detecting changes in an object from a plurality of images captured at a variety of camera positions, under a variety of lighting conditions, at a variety of angles and at a variety of scaling factors.
A method of detecting changes in an object from images taken in the space employs a still image which captures a region, and a plane value map or a solid value map. Specifically, one technique involves overlaying the map on the image to detect a new object from the image using a figure template (see, for example, JP-A-2000-310940), and another technique involves a comparison of a characteristic amount found from an input image with a characteristic amount found from a reference image to detect changes (see, for example, US 2002/0051572A1). This technique employs boundary information as a characteristic amount.
The prior art technique disclosed in JP-A-2000-310940 is incapable of detecting changes when an appropriate map does not exist. On the other hand, the prior art technique disclosed in US 2002/0051572A1 is incapable of determining a change using a plurality of properties including a geometric property, an image property, a relation property, and the like.